It is known that the strength and stiffness of thermoplastics can be increased by incorporation of glass fibers. A detailed description of this technology is described in the monograph by P. H. Selden "Glasfaserverstarkte Kunststoffe" ("Glass Fiber-Reinforced Plastics"), Springer-Verlag (1967), pages 307-344.
High molecular, thermoplastic aromatic polycarbonates are distinguished particularly by their good mechanical, thermal and electrical properties. In comparison thereto, glass fiber-reinforced, high molecular, thermoplastic aromatic polycarbonates have both substantially increased flexural strength and stiffness, and a substantially increased E-modulus. On the other hand, the impact strength, notched impact strength and elongation at break of glass fiber-reinforced polycarbonates are less than those of corresponding non-reinforced polycarbonates. The efforts, in the preparation of glass fiber-reinforced polycarbonates, are now aimed at increasing the adhesion between the fibers and the polycarbonate matrix by using glass fibers with suitable glass fiber sizing agents as well as additives and/or adhesion promoters, in order thereby to improve the tough-elastic properties of glass fiber-reinforced polycarbonate molding compositions, particularly also under damp climatic conditions.